1CHU (원츄) — a name that started as a small sub-unit and grew into one of the most quietly beloved acts in the 4th generation K-pop scene. If you’ve been curious about this South Korean girl group under MOAI Entertainment, you’re in the right place. Whether you’re a long-time Chuing (that’s what 1CHU’s fanbase is called!) or you’ve just stumbled across their music, this guide covers everything — from their band information and member profiles to their full discography, achievements, and live performances.
1CHU started as a K-pop duo consisting of Sulhee and Chaerin, originally a sub-unit of HeyGirls. After HeyGirls disbanded, 1CHU became its own standalone act. By early 2025, Chaerin became the sole active member, carrying the 1CHU name forward. It’s a story of resilience, passion, and some genuinely great music — and today we’re breaking it all down for you.
Band Information
- Group Name: 1CHU (원츄)
- Hangul: 원츄
- Origin: South Korea
- Genre: K-pop, pop, pop-punk
- Label / Agency: MOAI Entertainment
- Debut Date: July 12, 2022
- Debut Single: “OASIS”
- Original Formation: Sub-unit of HeyGirls (South Korea’s long-running girl group)
- Current Status: Solo act (active), with Chaerin as the sole member
- Original Members: Sulhee & Chaerin (duo)
- Current Member: Chaerin only (as of February 6, 2025)
- Parent Group: HeyGirls (disbanded December 26, 2023)
- Project Group Affiliation: PUZZLE (South Korean-Japanese project group)
- Official Fandom Name: Chuing (츄잉)
- Fandom Color: N/A (not officially announced)
- Generation: 4th Generation K-pop
- Social Media:
- Instagram: @1chu_official
- Twitter: @MOAI_1CHU
- TikTok: @1chu_official
- YouTube: 원츄 (1CHU)
The 1CHU Member Profiles
Sulhee
Sulhee (설희) is a South Korean singer-songwriter, born on March 8, 1998, making her a Pisces. She served as the Main Vocalist of 1CHU and was widely recognized for her warm, emotive singing voice. She is originally from Seoul, South Korea, and first joined HeyGirls on July 3, 2019. She left MOAI Entertainment in February 2025 after her contract expired.
Sulhee
- Stage Name: Sulhee (설희)
- Full Name: N/A
- Birthday: March 8, 1998
- Zodiac Sign: Pisces
- Nationality: South Korean
- Position in 1CHU: Main Vocalist
- Blood Type: N/A
- MBTI: N/A
- Height: Approx. 163 cm
- Role Model: Taeyeon (Girls’ Generation)
- Instagram: @heej_vibe
- TikTok: N/A
- Status in 1CHU: Former (left February 6, 2025)
She can play the piano — a skill that adds serious depth to her artistry as a vocalist.
Her nickname is “Snow White” (백설희, Baeksulhee) — a playful spin on her name that fans absolutely love.
Another nickname is “Sultato” — a fun mashup of “Sulhee” and “potato” that her fans coined.
Her favorite food is sushi — she’s mentioned it as one of her top comfort foods.
Her favorite season is spring — fitting for someone born in March with a warm, gentle stage presence.
She has a favorite scent: baby powder — which makes her personality as cozy as it sounds.
She co-wrote 1CHU’s song “Siren” — proving she’s not just a vocalist but a genuine creative force behind the music.
She absolutely hates scary things — horror movies? A hard no for Sulhee.
She was the Leader of PUZZLE — the South Korean-Japanese project group she was also a member of alongside Chaerin.
Her role model is Taeyeon — the legendary soloist from Girls’ Generation, whose vocals clearly inspired Sulhee’s own singing style.
Chaerin
Chaerin (채린), full name Park Chae Rin (박채린), was born on June 26, 2003, making her a Cancer. She is currently the sole active member of 1CHU and is also a member of the girl group E11iVYN under MOAI Entertainment. She joined MOAI Entertainment back in 2020 and has been steadily building her career ever since.
Chaerin
- Stage Name: Chaerin (채린)
- Full Name: Park Chae Rin (박채린)
- Birthday: June 26, 2003
- Zodiac Sign: Cancer
- Nationality: South Korean
- Position in 1CHU: Main Rapper, Vocalist, Maknae
- Blood Type: B
- MBTI: ESFP (formerly ENFP)
- Height: 166 cm (5’5″)
- Role Model: Joy (Red Velvet)
- Instagram: @0__chaerin
- TikTok: @o_chaer1n
- Status in 1CHU: Active (sole member)
She is originally from Bucheon, South Korea — a city in Gyeonggi Province, just west of Seoul.
Her favorite color is pink — and yes, she’s been spotted with pink hair to match!
She loves Hello Kitty — a true Sanrio girlie at heart.
Her MBTI type is ESFP — meaning she’s energetic, fun-loving, and loves being around people.
Her role model is Red Velvet’s Joy — specifically because of Joy’s unique voice and warm, infectious smile.
She is a self-confessed ATEEZ fan — so she knows good music when she hears it!
Her favorite Korean foods are Mulnaengmyeon (cold noodle soup) and marinated ribs — a girl with great taste in food too.
She is a fan of taking mirror selfies — her Instagram content proves it.
She is the Maknae (youngest member) of 1CHU — despite being only 5 years younger than Sulhee, she carries a playful, youthful energy.
She sang the OST “Tonight I Miss Everyone” for the MBC drama Love Class 2 in 2023 — marking her growth as a solo artist beyond group work.
Achievements
1CHU might be a relatively small act in the vast world of Korean idol groups, but their achievements are nothing short of impressive for an indie K-pop unit under a smaller label. Here’s what they’ve accomplished:
| Achievement | Details |
|---|---|
| First Sub-Unit of HeyGirls | 1CHU holds the distinction of being the very first sub-unit ever formed under HeyGirls — a historic milestone for the group. |
| Independent Group Status | After HeyGirls disbanded in December 2023, 1CHU became a fully independent group under MOAI Entertainment — a rare feat for a sub-unit. |
| Multi-Group Participation | Both Sulhee and Chaerin are members of PUZZLE, a South Korean-Japanese cross-cultural project group — showing 1CHU’s reach beyond the Korean market. |
| OST Contribution | 1CHU contributed to the official soundtrack of the MBC daily drama “하늘의 인연” (Heavenly Ties) in 2023, bringing their music to a broader TV audience. |
| Chaerin’s Drama OST | Chaerin solo-recorded “Tonight I Miss Everyone” for the MBC drama Love Class 2 (2023), expanding their presence in the Korean entertainment industry. |
| Versatile Sound Range | Over their releases, 1CHU has demonstrated an impressive range — from the dreamy pop of “OASIS” to the siren-call drama of “Siren” to the high-energy pop-punk of “Punk Hot”. |
| Continued Activity Post-Lineup Change | After Sulhee’s departure, Chaerin kept 1CHU alive as a solo act while simultaneously debuting with E11iVYN in October 2025 — showing remarkable dedication. |
| International Fan Base (Chuing) | Despite their nugu (underrated/underground) status, 1CHU has built a passionate global fanbase — the Chuing (츄잉) — with fans across Asia, Europe, and the Americas. |
Discography and Music Videos
1CHU may have a compact discography, but every release shows real growth and musical boldness. Let’s walk through everything they’ve put out:
Full Discography Table
| # | Title | Type | Release Date | Notes |
|---|---|---|---|---|
| 1 | OASIS | 1st Digital Single (Debut) | July 12, 2022 | Debut track; dreamy, atmospheric pop |
| 2 | SIREN | 2nd Digital Single | April 10, 2023 | Fan-favorite; co-written by Sulhee |
| 3 | 봄을 닮은 너 (You Who Resembles Spring) | OST Single | August 28, 2023 | MBC drama “하늘의 인연” OST Pt.5 |
| 4 | PUNK HOT | 3rd Digital Single | April 15, 2024 | Genre-shift into pop-punk; widely praised |
| 5 | It Was You | 4th Digital Single | May 3, 2024 | Includes instrumental version |
| 6 | Date With Me (사귀자) | 5th Digital Single | August 9, 2024 | Playful, upbeat love song |
Music Video Highlights
OASIS (2022) — The debut music video that introduced the world to 1CHU. It captures a gentle, hazy aesthetic that perfectly matches the song’s breezy, emotional K-pop sound. The video showcases Sulhee’s powerful vocals alongside Chaerin’s rap flair in a cohesive package that immediately told fans: these two have chemistry.
SIREN (2023) — This music video ramped up the drama and showcased a more mature, atmospheric side of 1CHU. Notably co-written by Sulhee herself, “Siren” became arguably their most critically well-received track, earning strong fan engagement and putting them on the radar of K-pop listeners who love layered, emotionally rich music.
PUNK HOT (2024) — Easily the most talked-about music video in their catalog. This genre-pivoting release into pop-punk surprised fans in the best way possible. The video features sharp outfits, high energy, and a completely different side of 1CHU that proved they can pull off virtually any musical concept. Fans in the comments went wild — phrases like “pure charisma” and “this fits them perfectly” flooded the video feed.
Live Performances and World Tours in 2026
As a smaller MOAI Entertainment act, 1CHU’s live performance schedule has primarily focused on domestic Korean performances, fan events, and project group activities through PUZZLE. Here is what’s confirmed and what’s scheduled:
Note: 1CHU does not currently have an announced standalone world tour for 2026. The live performance history below covers confirmed events tied to Chaerin (1CHU’s active member) and the group’s known appearances through 2025 and early 2026.
Live Performances & Events Table
| Event | Type | Date | Location | Notes |
|---|---|---|---|---|
| 1CHU Debut Showcase | Debut Performance | July 2022 | Seoul, South Korea | Debut performance of “OASIS” |
| PUZZLE Debut Performance | Project Group Live | November 2023 | Seoul, South Korea | As part of the Korean-Japanese project group |
| AMF Pink K-Pop Concert | Fan Concert | May 4, 2025 | South Korea | Chaerin performed as 1CHU / E11iVYN pre-debut appearance |
| Gyeyang Residents’ Day Autumn Concert | Public Event | October 2, 2025 | Gyeyang, Incheon, South Korea | E11iVYN (incl. Chaerin) announced debut date here |
| E11iVYN Debut Showcase | Debut Live Event | October 30, 2025 | Seoul, South Korea | Chaerin performed with E11iVYN; 1CHU activities ongoing in parallel |
| Fan Meetings / MOAI Events | Fan Interaction | Throughout 2025–2026 | Seoul, South Korea | Ongoing small-scale fan engagement events |
| TBA – Potential 2026 Comeback Stage | Music Show Performance | Expected 2026 | South Korea | No official announcement yet as of May 2026 |
2026 Tour & Activity Outlook
As of May 2026, Chaerin continues to manage both her 1CHU solo activities and her role as a member of E11iVYN. While no large-scale 1CHU world tour has been confirmed for 2026, here’s what fans can look forward to:
- A potential 1CHU comeback is anticipated by the Chuing fanbase, given Chaerin’s pattern of releasing music annually since 2022.
- E11iVYN’s growing schedule includes music show promotions following their debut single “Orbit” (October 2025), which means Chaerin’s stage presence will remain strong throughout 2026.
- Fans in international markets — particularly in Southeast Asia, Japan, and Europe — have been vocal on social media about wanting a 1CHU fan meeting or showcase, which could become a reality as the fanbase grows.